Apparatus for regulating the temperature of furnaces and the like.



R. L. BAKER.

APPARATUS FOR RE GULATING THE TEMPERATURE OF FURNACES AND THE LIKE. APPLICATION FILED NO.\I- 25 1912.1

1,170,727. Patented Feb. 8,1916.

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I R. E. BAKER; A APPARATUS FOR REGULATING THE TEMPERATURE OF FURNACES AND THE LIKE.

' APPLICATION FILED NOV- 25| 1912.

1,170,727. Patented Feb. 8,1916.

3 sums-sum 2.

R. E. BAKER. APPARATUS FOR REGULATING THE TEMPERATURE OF FURNACES AND THE LIKE.

'APPLICATION HLED Nov. 25,1912. 1,170,727. Patented Feb. 8, 1916.

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UNITE STATES j PATENT OFFICE.

ROBERT E. BAKER, OF CLEVELAND, OHIO, AS SIGNOR TO ARTHUR G. MGKEE.

APPARATUS FOR REGULATING THE TEMPERATURE FURNACES AND THE LIKE.

Specification of Letters Patent.

Application filed November 25, 1212. Serial No. 733,459.

To all whom it may concern .1

Be it known that I, ROBERT E. BAKER, a citizen of the United States, resident of Cleveland, county of Cuyahoga,and State of Ohio, have inventeda new and useful Improvement'in Apparatus for Regulating the 7 control.

- The object of the invention is to provide means to automatically maintain the temperatur of such furnace, crucible, other receptacle or object, Within certain prede tel-mined limits.

The said invention consists of means here- 3 inafter fully described and particularly set forth in the claims.

The annexed drawings .and the following description set forth in detail certain means embodying my invention, the described means, however, constituting but one of various mechanical forms in which the principle of the invention may be "applied.

In said annexed drawings :Figure 1 is a diagrammatic illustration of an apparatus embodying my invention. Fig. 2 is-a plan -'of a gal'vanometer embodied in my invention. Fig. 3 is a section of such galvanometer taken upon the plane indicated by line III-III in Fig. 2. F ig. 4 is a horizontal c section of such galvanometen. Fig. 5 is a section of such galvanometer taken .upon the plane indicated by line VV in Fig. 4. Fig. 6 is a perspective view of a fragmentary portion of the galvanometer. Fig. 7 is a perspective view of one of the magnets embodied in such galvanometer.

Certain features of the described and illustrated apparatus are, however, shown, described and claimed in a separate application for Letters Patent,- said application bearing Serial No. 842,536, and having been filed June 2, 1914.

In the apparatus illustrated by the draw- I ings as embodying my. invention, A, Fig. represents a furnace or crucible whose temperature it isdesired to measure .and cantrol. Projecting 'into this furnace or crucimeans of suitable insulation 0.

securing magnets D D to said bar.

ble at a suitable place is an ordinary thermocouple B connected with the galvanometer C in the usual manner, so that a variation of temperature in the furnace, will effect a deflection of the indicating pointer or nee dle C of the galvanometer. The latter is provided with the usual graduations c. The outer end of the needle consists of a nonmagnetic material, preferably a metal such as aluminum, and, where the balance of the needle is also of aluminum or a similar conducting material, is insulated therefrom by This outer portion ofthe needle carries a small armature C which hence has a path of movement defined by the arc of a circle, as will be readily understood.v Adjacent to the armatures path of movement and having their end faces parallel with such path,are the cores d d and d of three magnets D D and D respectively. The coils of these'magnets are connected in series in an electrical.

circuit E containing a battery E, Fig. 1.

In the specific form of device illustrated,

'- the faces of the cores d d are made equal in length and each of such faces is made of suitably greater length than the face of the core d, the latter being equally spaced lat erally from said first named two core-faces, as shown in Fig. 2. Each of these three magnets is. mounted upon a segmental bar F, Fig. 4, which itself is provided with a multiplicity of spaced guiding lugs f, Fig. '6, which travel in a segmental groove 9,

Figs. 4' and 5, formed in the frame of the galvanometer. The magnet D is removably secured to the bar or carrier F by means of a suitable screw f, Fig. 3, passing through a circular aperture 7, Fig. 6, located between two of the guiding lugs f, whereby 1t is seen that the magnet may be readily removed and replaced by-a second magnet. Laterally of the said aperture f and also located between adjacent lugs f are elongatedslots 7 through whlch pass screwsBf 3 means of these elongated slots it will be seen that the position of these" last two named magnets may be adjusted l0ng1tud1- nally of the bar, with reference to each other and to the central or intermed ate magnet D, such adjustment being limited I Patented Feb. 8, 1916.

by the length of the elongated openings or 3, 4 and 5, which engage one edge thereof,

and a strip Fig. 5 which engages a groove f formed adjacent to the other edge of the bar. The latter is furthermore formed near its outerand upper edge with bevel-gearteeth 7 which are engaged by a bevel-pinion c" suitably mounted and operable through the medium of a thumb-wheel c projecting from the outer portion of the galvanometers casing. It will therefore be seen that by.

turning the thumb-wheel c the carrier F together with all of the magnets may be si- 1 multaneously shifted in a direction parallel with the path of movement of the' small armature C The magnetic field which is setup by these magnets is therefore intersected by the path "of movementof said armature, and is also shiftable in the directioni' of movement of the latter.

Suitably mounted and fixed to the galvanometers casing is a segmental contact strip H having its up-per or contact surface parallel with the path of movement of the outer end of the galvanometer needle and placed in a position such that the movement of the armature 0 toward any one of the magnet cores, will eifectcontact-between the outer end of the needle and such surface.

This contact strip is of a length suflicientto effect such contact in all 7 positions into which the carrier F and magnets mounted thereon may be' shifted.

Mounted upon each of the cores d 'dof magnets D D, is a contact strip, H H, having an outer segmental contact surfacecoextensive as to length with the outer face of the core, such surface being located in the plane of the contact surface of the strip H. These two strips form an auxiliary, interrupted and'elongated contact surface which is also capable of being engaged by the end of the needle C, when subjected to movement as a result of the attraction of the armature (1?. Such action, it will therefore be observed, will result in the electrical connec tion of the continuous contact surface of the strip H and an interrupted contact surface formed by the strips H H, when the needle C -1s opposite either of the magnets U D.

When theneedle is'opposite the magnet D,

the contact strip H alone will be engaged bv the said needle. I

The contact strip H forms a terminal in the circuit E as shown in Fig. 1. This circuit contains a circuit breaker J adapted to periodically make and break same at predetermined intervals. This circuit breaker gaged.

may be of any suitable construction, but. as. illustrated embodies a circular disk J rotated at a uniform rate of speed by any suitable mechanical or other means (not shown) and which 9is constantly engaged by the resillent terminal 6 1n thecircuitE. A second resilient terminal 6 also in sald c rcuit, lies in the path of a projection j formed upon the disk, the length of the engaging surface of this projection being such as'to produce the required period .of contact and hence of completion of the circuit E. From the construction as thus far described it will be seen that at predetermined intervals the circuit E ,w'ill be completed fora predetermined 30 length of time, armature C attracted and the terminal strips H and H connected, at such times when theneedle is opposite the magnets D D. -When the needle is opposite the magnet D and the circuit E is like- 35 wise periodically completed, the armature is attractedbut only the contact strip H en- The one terminal strip H is connected witha circuit K, Fig. 1, including the coils of a magnet K adapted to operate a relay switch L." This circuit K also contains the battery E. The other-contact strip H is connected with a circuit K including the coils of a second magnet K 'adapted to opcrate a second relay switch L. This circuit K also contains the battery A main feed or. supply circuit M is provided and connected therewith are two parallel circuits-M. and M containingrespec lw ftively the terminals m and m with which the relay switches L and L are normally out of-"engagement but adapted to engage when the respective magnets. K and K are energized. The circuit M contains the coil of a solenoid M whose core 'M" is-connected with a rack M This rack engages a pimon M connected in any suitabIemanner with a valve, damper or any other device (not shown) capable of-controlling the tempera ture of the furnace or the like, such device being, as'will be readily understood by those skilled in the art, suitably located for this I purpose. The other parallel circuit M con' tains thecoil of a second solenoid M,- coaxial with solenoid M and whose core M is connected to-athe other .endof the rack M When the solenoid -M is energized, the rack is drawn in one direction to operate the valve to increase the temperature of the furnace and when the solenoid M is energized the opposite movement is efl'ected to produce a decrease of such temperature. A suitable dash-pot P. is provided inwhich operates a .piston P connected with; the solenoid-core ,125 M through the medium of a suitable piston-' rod 11. As will be understood this dash-pot is provided in order to arrest and control the movementof the solenoid cores.

The above deacribeddevice operates as 1 4 J revolving about its axis at a maintain same within whose extreme members define such limitations of -temperature. This position is imparted by turning the thumb-wheel c 'as previously described. Let it now be assumed that the temperature of the furnace is of a degree less than the minimum temperature which it is desired to maintain. The needle of the galvanometer therefore will be opposite say the left-hand magnet D. The disk given period closes the circuit E, whereby the magnets DD andD become energized, the armature C is attracted, the contact strips H and the corresponding contact strip H are connected, thus closing the circuit K. a This action energizes the magnet K which thereupon effects the movement of its armature connected with relay switch L. This movement brings this switch into contact with the terminalm and closes the circuits M and M, the circuit M remaining open as a result of the non-engagement of the terminal m and switch L. As a result, solenoid M is energized and the valve or other device operated to increase the temperature of the furnace. As a consequence the needle of the galvanometer advances to indicate the temperature thus produced. Successive increases oftemperature are in a like manner produced until the temperature reaches a point beyond the minimum temperature desired. When this occurs the needle reaches a position opposite the intermediate magnet D and in the subsequent closing of the circuit E becomes inoperative in so far as concerns the closing of the circuit K and hence the operation of the valve or temperature controlling device. Should now for any reason or combination of circumstances, the temperature of the furnace rise above the maximum temperature desired, the needle reachesa position opposite the other of the magnets D. In this event the periodic closing of the circuit E closes thecircuit K causing the switch L to engage terminal m and close the circuits M and M This results in the energizing of the solenoidM and the opposite movement of the valve or temperature controlling device, as will be readily understood. In this manner it will be seen that the temperature of the furnace may be automatically controlled so as to certain specific and predetermined limits. If it is desired to change these limits the intermediate magnet C is removed and a magnet substituted there- 'for'having a core of different width, the

magnets D D being adjusted upon the carriage F correspondingly.

Having fully described my invention,

what I claim and Patent is 1. In apparatus for regulating the temperature of furnaces or the like, the combination of means for varying the temperature of said furnace or the like; electrical means for controlling the operation of said temperature-varying means; electrical means for controlling" the first-named controlling means; andseparate electrical means for recurrently completing a circuit in said last.- named controlling means, at predetermined periods of time. i

2.. In" apparatus for regulating the temdesire to secure by letters perature of furnaces or'the like, the combination of means for varying the temperature of said furnace or the like; electrical means for controlling the operation of said temperature-varying means; electrical means for controlling the first-named controlling means; and separate electrical means for recurrently completing a circuit in said lastnamed controlling-means and independently of temperature.

3. In apparatus for regulating the temperature of furnaces or the like, the comb1- nation of a temperature-lndlcatom means for varying the temperature of sald furnace or the like and including a source of motive-power; and means for controlling said source of power and including an electrical circuit controlling a magnet1c field and means for interrupting such c1rcu1t periodically, and a second'electrical circuit directly controlling said controlling means and including a cir c uit-closing member carriedby the indicating member of sald 1ndicator and located in said magnetic field.

4. In apparatus for regulating the temperature of furnaces or the like, the combination of a temperature-indlcator; means for varying the temperature of said furnace or the like and including a source of motivepower; and means for controlling said source of power and including an electrical c1rcu1t controlling a magnetic field and means for interrupting such circuit periodically; and a second electrical circuit directly controlling said controlling means and lncludlng a circuit-closing member controlled by the indicating member of said indicator and perature of furnaces or the like, the combination of a thermo-couple; a galvanometer electrically connected with said thermo-couple; a system of electro-magnets; means for regularly and intermittently energizing said magnets; means for completing an electric circuit through the needle of said galvanometer by attraction of said needle by said magnets; an electric current switch operated through the closing of saidelectric circuit; and a magnetically operated valve controlled by said electric current switch.

7. In apparatus for regulating the temperature of furnaces or the like, the combination of athermo-couple; a galvanometer electrically connected with said thermo-couple; a series of electric magnets located beneath the plane of the needle of said galvanometer; means for moving said magnets in a parallel plane with said needle-plane; means for intermittently energizing said magnets; a magnetically operated electric current switch; means for operating and controlling said electric current switchthrough an electric current controlled by said galvanometer and electro-magnets; and a valve magnetically operated and controlled by said electric current switch.

8. In apparatus for regulating the temperature of furnaces or the like, the combination of an electricallv operated pyrometer; a series of electro-magnets located beneath the plane of the needle of the indicating instrument of said pyrometer; means for energizing said magnets at controllable time intervals; means for changing the position of said magnets; an electric current switch electrically operated and controlled through v closing of an electric circuit upon attract1on of said need-1e by sald electro-magnets; a valve; and operatlng means for sald valve controllable through the operation of said D electric current switch.

9.. In apparatus for regulating the temperature of furnaces or the like, the combination of a thermo-couple an electrical current indicating instrument electrically con- 7 nected with said thermo-couple; a series of electro-magnets; means for intermitently energizing said electro-magnets; an armature attached tothe needle of sa1 d lndicating instrument and so located 'aS to be attracted ROBERT E. BAKER. Attested by-' WM. R. MILLER, D. FINDLING. 

